| 摘要 |
<p>A liquid flow control valve has a valve body (10) in which is mounted a valv e member (41) moveable between valve open and closed positions. A turbine (15) senses liquid flow through the valve body (10) and generates electrical pulses which are counted by a control circuit, over a pre-set period. An electro-magnet (54, 55) controls operatio n of the valve member (41) and is driven by the control circuit so as to close the valve in the event that flow continues for longer than th e pre-set period or the flow is greater than at a pre-set rate. The valve may also be closed should the temperature fall to about 0.degree.C.</S DOAB></p> |
